The world of physics lost two highly respected figures when Louis Néel, the French Nobel prize winner, and Lochlainn O'Raifeartaigh, one of Ireland's most distinguished physicists, died within days of each other earlier this month.
Louis Néel was born in Lyons in 1904 and dedicated his career to the study of magnetism. In 1932 he discovered antiferromagnetism – a form of magnetism in which the ‘spins’ on neighbouring atoms point in opposite directions. Previously only three forms of magnetism – dia-, para- and ferromagnetism – were known. During the Second World War, Néel worked on the defence of French war ships against German magnetic mines.
In 1940, he set up the Laboratoire d’Electrostatique et de Physique du Métal, which six years later became part of the Centre National de la Recherche Scientifique in Grenoble. He went on to share the 1970 Nobel Prize for his discovery of antiferromagnetism, which has formed the basis of modern magnetic theories. He received dozens of awards during his career and was honoured by France, the Netherlands, Germany, Romania, the UK, and the US. Néel died on 17 November.
Lochlainn O’Raifeartaigh was born in Dublin in 1933 and was associated with the Dublin Institute for Advanced Studies for most of his career. His research concentrated on the applications of group theory to physics, gauge theory and supersymmetry. He made his name in the mid-1960s with a “no-go” theorem which showed that the imposition of a certain symmetry group on a theory would allow for the possibility of a unified description of particles with different internal symmetries.
In later life he became renowned for his work on the history of gauge theory and one of his last publications was an article on this subject in Reviews of Modern Physics (vol. 72 pp 1 – 23). He also wrote several books on gauge theory and recently received the Wigner medal for his “pioneering contributions to particle physics.” He died on 18 November.
